Atomizing type oil fogger



M. G. MARKLE Er AL ATOMIZING TYPE on. FoGGER Jan. l2,v 1937.

5 Sheets-Sheet 1 Filed Dec. 1 A 1932 Jan. 12, 1937. M Q MARKLE Er AL 2,067,454

` ATOMIZING TYPE OIL FOGGER Filed Dec. l, 1932 5 Sheets-'Sheet 2 Z/n PERA TURE Jan. l2, 1937.

M. G. MARKLE ET AL ATOMIZING TYPE OIL FOGGER Filed Dec. l, 1932 5 Sheets-Sheet 3 Jan. 12, 1937. M. G. MARKLE Er AL ATOMIZING TYPE OIL FOGGER 5 Sheets-Sheet 4 Filed Deo. 1, 1932 M B D@ JV fw m M m I Il Il u! Zaren WJZMQZQ.

Jan. 12, 1937. M, G MARKLE AL 2,067,454

ATOMIZING TYPE OIL FOGGER Filed Dec. 1, 1932 5 Sheets-Sheet 5 @y Vc @a atenter `lain. l2, i937 UNITED STATES ATSENT oFF-ICE ATOMIZING TYPE oIL FOGGER Mathew G. Markle, Maywood, and Loren W.

Tuttle, Mount Prospect, Ill.

This application is a continuation in part of our pending application Serial No. 561,629, filed September 8, 1931.V

CombustibleA gas for fuel and illumination is widely distributed through pipe lines and conduits provided with expansion joints, valves, cocks and the like where there is opportunity for leakage to occur. It has long been known that if the packing and surfaces ofvsuch fittings are kept wet with oil or an oily liquid, the leakage can be greatly reduced if not substantially eliminated.

In artificial gas the process of manufacture provides or can readily provide the necessary amount of sealing liquid to be carried by the gas for thus sealing the minute openings which would otherwise pass gas and thereby permit leakage.

' Natural gas, the distribution of which from remoteelds and over wide areas is now rapidly progressing, is very dry. It containsno appreciable amount of oil or like liquid and,in fact, it not only fails to supply the desired liquid seal or lubricant, but actually tends to dry it up whereever provided. Other dry gases besides natural gas have the same tendency. As a result, it has been found necessary to provide the desired liquid content by injecting into the gas finely divided oil,

" ried along with the gas to relatively great disc-eive to be a far superior method of forming the tances so that it will wet or lubricate the fittings such as cocks, valves, etc. at all points in the system to keep the same tight. Any excess oil fog which does not deposit upon the surfaces desired merelypasses on with the gas into the burners and is consumed. It has been attempted heretofore to form a suitable oil fog, but so far as we have been able to ascertain the means and methods heretofore employed have been expensive and wasteful.

'Ihere are a number of reasons for this which will more plainly appear from the following speciiication describing the construction and practice of our invention, but chief among these reasons, as we believe, is that previous oil foggers have proceeded upon the theory of forming the fog from hot oil, or form and utilize the same in such manner as not to secure the full benefit of the thermodynamic action. We provide what we conable to say with certainty just what the. full eX- planation ofthe persistence of our fog is, but we submit the following as our present theory of the action involved:

We conceive that the size of a particle of liquid which will be carried av certain distance in a 5 stream of gas of a given composition moving at a certain velocity is substantially xed. If the temperature of the gas drops, the size of the liquid particles does not change appreciably, but the drops approach each other more closely because l0 of the shrinkage of the body of gas. Also, if any of the oil in vapor form is present, it tends to condense upon' the particles in liquid form. Hence, weconceive that formation of the fog hot and subsequent chilling of the same4 is unfavorable to a l5 maximum of persistence. Our experiments and observations confirm this theory.

l According to our process, the fog is formed cold and is introduced into the gas which is preferably at a temperature higher than that of the 20 fog. A

There are a number of practical advantages flowing from this mode of operation. First, there is no necessity for applying heat. This avoids expenseof apparatus and heat, and avoids the difficulties of maintenance which heating apparatus entails. Second, due to the greater persistence of the fog, a higher economy of oil is secured and the effect is more far reaching.

The means which we employ involves a number of novel features, some of which are the followingz-The fog lproducing nozzles are Venturi nozzles and serve not only to atomize the oil, but also, and this is important, serve to meter it in a fairly close proportion tothe gas passing through the same.

'I'he fogging chamber serves as a separating chamber to separate out any particles which are too large to be transported by the current of gas. This separation is performed partly by centrifu- 4.0 gal separation and scrubbing against the walls of the chamber and also partly by gravity. Wt arrange to produce a less or greater separatingV action by adjusting the position of the outlet in the chamber.

In order to secure the necessary pressure difference to develop an atomizing effect, we dispose the oil fogger in shunt of a pressure reducing valve so that from 3 to 5 pounds pressure dilerence is available. Our invention is not dependent upon use ofthe fogger at this particular location, but important practical advantages are thereby secured. It may be desirable to introduce fog as a vpoint where no pressure reduction is made. In that case, means such as a pump may be employed to make the necessary pressure difference to secure proper atomization.

It is not desirable to force all the gas to pass through the fogger because of the size of the unit which would be required. By forming the fog with a part of the gas and delivering the fog into the main stream of gas, it is possible tc keep the apparatus small in size and, at the same time, secure the advantage of delivering the fog cold into a slightly warmer body of gas. The main flow of gas passes through the main pressure regulator where it expands from a suitable transmission pressure to a suitable distribution pressure, but with no substantial change in temperature. 'I'he fogging stream of gas which always proportional to the main stream does the work of atomizing the liquid and suiers an appreciable drop in temperature. 'The two streams unite and carry a highly persistent fog.

Another feature of our invention resides in the provision of means for keeping a substantially constant level of oil in the fogging chamber. The fogging chamber contains in its lower end a body of oil from which the nozzles draw oil for atomization and into which the larger `particles thrown out by the separating action are returned. yA further feature of novelty resides in the supply means for maintaining the desired oil level and the means for recharging said supply means with oil.

Other objects and advantages will-be apparent from a consideration of the following specication and accompanying drawings wherein:

Figure l is a plan view, in partial section, of a fogging stationV embodying the present invention;

Figure 2 a vertical'sectional View taken on line 2-2 of Figure 1;

Figure 3 is an enlarged diagrammatic elevation of the atomizing chamber and oil supply tank and oil ifeed regulating and charging rconnections;

` Figure 4 `is a horizontal sectional view of the atomizing chamber and associated gas pressure regulators;

Figure 5 is a longitudinal'sectional View of an atomizing nozzle;

Figure 6 Vis a graph illustrating, in a general way, the relative vtemperature of the gas after passing through the gas regulators with lreference to the temperature of the gas fog after pass- K passes from a main to a lower pressure section in the groundat a proper depth. 'In the drawings vsuch a structure is indicated at I0, and passing through the same is a gas conduit the high pressure side'being at the Vbottom of the gure. The gas flows Vin the'directionindicated by the .arrow I2 and passes through the automatic pressure reducing valve or regulator I3 of conventional construction. Manually operable valves I4' and I5 generally are provided for use as may be required. The gas, after passing through the valve I3, enters pipe I6 at suitably reduced pressure. 'Ihe drop in pressure from the higher pressure side to the lower pressure side may be any usual or preferred amount, but should, in the present construction, be about 3 to 5 pounds' per square inch. The pressure on the gas consumption outlets connected to pipe I6 is of the order of 6 inches of water.

The fogging apparatus of the present improvements may readily be installed in manholes of the type mentioned or in any other location. The apparatus comprises an atomizing tank I'I and oil reservoir I8 and associated parts. The tank |'I as shown is provided with a plurality of atomizing nozzles I9 which are connected through suitably shaped elbows 20 to fittings passing through and fixed to the iioor of the tank. The nozzles I9 preferably are disposed at an angle to the horizontal, as shown in Figure,y and also at angles with respect to the radii ofthe base of the cylindrical tank jII asfillustrated in Figure 4 to give the discharge from the nozzles a helical up- Ward travel within-thetank |'|.V f I A pipe 2| forms a by-pass about the main pressure reducing valve I3 and conveys gas from the higher pressure conduit II to a manifold having branch pipes'or headers 22, 23 and -24 as illustrated in Figure 4. Y

The gas flowing `through pipe 2| is utilized in the nozzles I9 for atomizing the oil and for carrying the oil fog lthus formed into the low pressure main through the pipe'3l.

Between the pressure'- regulator I3 and the pointon the low pressure mainwhere the pipe 3| vjoins the same, we have introduced a tting, including'an 'oriiice'pl'ate 50 as shown in Figure l. The function of the oriiice plate is to provide a pressure diierence having a deiiriite relation to that part'of the main gas ilow through the pipe I6 which islater joined by the stream of fog carrying gas. It is desirable that thev ilow of gas through theby-pass 2|, tank II `and pipe 3| should be proportional to the ilow through the orifice platel 50, so that the amount of fog is proportional to thetotal amount of gas flow. Diaphragm control valves 26 and 21 are connected in the branch pipes 22 and y2li and are controlled by the pressure difference created by the orifice plate 50. The entire flow of gas through the pipe 2| passes through a diaphragm control valve 25, and then joins the manifold to which pipes'22, 23 and 24 are connected. The valve 25 is a shut-off valve which is operated by a diaphragm 'to shut oi the flow of gasy through the pipe 2| when the pressure on the delivery side of the regulator exceeds a predetermined value. We have shown the diaphragm chamber of this valve 25 as connected to the low pressure main I 6 through Ythe connection 52. The iiow of gas to thefogging unit through the pipe 2| and the. branch pipe 23 and the two nozzles` connected thereto is designed to be sufficient to supply the nighttime load. If, however, the feed through the pipe 2| should be so excessive as to increase the pressure in the main I 6 abovepredetermined value, this presdiaphragm chamber of the -valve 25 shuts off the by-pass 2|, stopping further operation of the sure acting through the connection 52 Vand the 170 fogging device or the flow of` gas through said by-pass 2 I The diaphragm chambers of valves 26 and 21 are connected by suitable pipes 53 and 54 to the opposite sides of the orifice plate 50. The valve 26 is designed to open with a snap action at a suitable pressure difference corresponding to a denite flow through the pipe I6. Similarly, the valve 21 is designed to open with a snap action for a higher pressure difference corresponding to higher i'low at pipe I6. 'Ihus the number of nozzles which are active to form fog are proportioned roughly, or approximately, to the flow of gas through the orifice plate 50. If a closer approximation is desired a greater number of valves, such as 25 and 26, may be provided, as one valve for each nozzle, the valves being set to operate at pressure dilerences corresponding to diierent gas velocities through the orice plate 50.

The valves 25, 26 and 21 are snap action valves, that is, close and open sharply, inasmuch as no throttling action upon the nozzles is desired, full pressure of the gas being necessary for proper atomizing operation of these nozzles.

In Figure 9 we have shown in detail one manner in which the valves 25, 26 and 21 may be regulated. For example, the valve 21 may comprise a valve housing member in the conduit 24, having a valve member 92 movable toward and away from a valve seat formed in the housing. The housing 90 is also provided with a pair of pressure chambers 93 and 94, the pressure chamber 93 being connected through the pressure line 53 to the inlet side of the ow restriction orifice 50 while the chamber 94 is connected through the conduit 54 to the outlet side of the restriction orice. In this manner the difference of pressure on opposite sides of the restriction is transmitted to the chambers 93 and 94 which are separated by a flexible bellows member 95, which may be of a corrugated type or of a dishshaped type capable of giving snap movement to the valve member 92 which is normally urged toward closed position by means of the spring 96. It is thusapparent that as the pressure in the chamber 93 increases, the valve 92 will open away from the valve seat, allowing flow of gas through the Vconduit 24. When the ow through the distribution conduit is decreased so that only a small difference of pressure exists on opposite sides of the restriction 59, the pressures in the chambers 93 and 94 will be substantially equalized and the valve will snap toits closed position under the inuence of the spring 96. Thus it is apparent that opening and closing of the valves 26 .and 21 will occur in accordance with the pressure differences on opposite sides of the restriction member 50. In the same manner, the conduit 52 may be connected to a chamber controlling the movement of a diaphragm for the valve 25 in which the lower chamber may be open to atmosphere, if desired. In this manner, the pressure in the conduit or main I6 will determine whether or not the valve 25 will be opened.

[When higher pressures are available so that atomizing is eiective even if throttllng is practiced, these valves may be made of the throttling type to control the ilow or gas through the fogging unit in proportion to the flow through the main gas ow.

The nozzles I9, shown inl detail in Figure 5, may each comprise a threaded socket by means of which it is secured to the fitting or pipe nipple 20. The type of nozzle illustrated in Figure 5 is a. Venturi nozzle which has a longitudinal passage which, at I 9b, is constricted to form a throat, while the remainder of the passage I9c increases in cross-section to the outer end of the nozzle.

Extending through the wall of each nozzle I9 is an oil feed tube 28, the inner end of which projects into the passage I9c a short distance beyond the constriction I9b. The outer or lower ends of the tubes 28 project beneath the surface of the oil 29 which is maintained in the bottom of the tank I1 at substantially a constant level.

The gas in passing through the nozzles I9 is accelerated in velocity by the constricted opening.` I9b with a consequent reduction in pressure, and this reduction in pressure draws oil through the tubes 28 and the velocity of the gas effects the atomization of the same. 'Ihe angular disposition of the nozzles I9, as above described, results in the body off gas and oil fog within the tank being given a. swirling or helical motion with the result that the larger particles of the oil mist are carried by centrifugal force toward and against the vertical wall of the tank to secure a so-called scrubbing action. Such heavier particles will coalesce or condense and drop to the bottom of the tank into the body of oil 29 or be throwrr against the walls, to which they adhere and down which the deposited liquid gravitates. This provides a direct return of the precipitated or separated oil without any separate return connections. Suitable baflles 29a, as shown in plan view in Figure 4, may be provided toI limit or prevent the swirling of the body of oil 29 in the bottom of the tank by the whirling action of the gas therein. Those baiiles extend upwardly from a point adjacent the bottom of the tank to immediately above the top of the liquid 29.

The oil fog passes from the tank I1 preferably through a sleeve 30 which is vertically adjustable along the pipe 3I. When the sleeve is in its highest position only such oil particles as are ne enough to be carried by the gas will pass through the pipe 3l into the lower pressure gas conduit I5 which conducts the gas to be treated with the oil fog. If a coarser quality of fog is desired, the sleeve may be lowered to limit the centrifugal scrubbing action.

As the gas anrd oil fog pass through the passages I9c of nozzles I9, the expansion of the gas results in a lowering of the temperature thereof in accordance with, first, the Joule- Thompson effect and, second, the laws of Boyle and Charles, because of the loss of heat incident to the work done in atomizing the oil. I'his reduction in temperature of the gas anxd the oil particles below the temperature of the gas current flowing in the pipe I6 increases the capacity of the oil fog to persist longer in the form of small particles and thus travel a relatively greater distance within the gas system for the reason that upon the admission of the lower temperature oil fog into the gas stream in the pipe I6, the relatively high temperature of the gas tends rst to expand the gas carrying the fog, thereby separating the oil particles, and second, to evaporate oil from the surface of the oil particles. This latter action results in the oil particles being further reduced in size and to thereby become more easily carried, hence more persistent. In the oil fogging of gas as heretofore carried on, insofar as we are aware, the oil particles of the fog are not so reduced in temperature at the point of admission.A intoy the gas stream as to secure any appreciable benecial effect. If the oil particles are of a higher temperature than the gas stream, the body of gas carrying the particles upon contact with the colder main stream of gras will contract and thus bring the particles closer together. Also, the chilling tends to condense any vapor upon the liquid particles, thereby increasing their size. The relative temperature of the gas passing through the governor or regulator and of the gas carrying the fog are illustrated in Figure 6.

Another features of the present invention which assists in effecting the improved results is that there are vno pipe connections at the outlets of the r'nozzles I9 to prevent or limit the full expansion of the gas and oil fog or to effect a scrubbing action on the oil and cause the particles to coalesce. The freedom of the fogv to expand upon leaving the nozzles, the separation of the larger from the finer particles and the conveying of the latter to the main gas stream at a reduced temperature results in the more persistent fogging of the gas.

As mentioned above, the sleeve 30 can be adjusted vertically. When the sleeve is in its highest position only the lightest or finest oil particles will be passed from the tank I1, whereas if the sleeve is lowered fog comprising larger oil particles can be conducted into the gas stream. The sleeve 3i) is merely an illustration of means for varying the character of the fog that is conveyed to the gas stream.

" The flow of gas to the nozzles I9 may be controlled by lany suitable means, as by individual shut-off valves Isa beneath the tank I1 or by a valve Zia in pipe 2l. The atomization of the oil may also be controlled automatically if desired, as by diaphragm valves which are responsive to1 pressure variations in the outlet pipe I6 of the governor or regulator I3, or the nozzles may be turned off and/ or on by hand or by clock mechanism according to a time schedule.

While I have shown the nozzles I9 located Y within the tank I1, it is within the purview of the present invention to locate the nozzles outside of the tank with the discharge ends of the nozzles opening into the tank through the cylindrical wall thereof.

It is desirable to maintain the supply of oil 29 in the tank I1 substantially constant and for effecting this object constant level supply apparatus is shown in detail in Figure 3. The reservoir oil tank I3 has a transverse partition or false bottom 32 therein through which a short tube 33 projects into the constant level chamber 34. A connection comprising pipe 35, a threeway valve 36 and pipe 46 connects the chamberY When the three-way valvev 34 with the tank I1. 36 is in the position shown in Figure 3, oil can flow to the tank I1 to compensate for the `oil which passes out as fog, and maintain in chamber I1 the same oil level as prevails in chamber 34. A pipe 50 extends from the upper part of tank I1 to valve 45 which, in normal position, connects pipe 50 to pipe 31 and this in turn. extends to a mercury seal and indicator 38 which in turn is connected to a short pipe 39. Extending from the pipe 39 are branches 43 and 4I, the former of which extends to the top of the reservoir I3. The branch 4I communicates with a mercury displacing device, which in the form illustrated, comprises a cylinder 43 provided with a manually operable piston 44. The three-way valve 45 has a pipe connection 5| to the top of chamber'34 which, when the valve 45 is in the' position shown in Figure V3,'permits gas pres- Figure 3. When the valves 35 and` 45 and the piston 44 are in theposition shown, oil from chamber 34 can flow through pipes 46 and 35 to the tank I1 to maintain ther oil therein at the proper level, the connection through pipes 5| and 5!) serving to equalize the pressures inthe chamber 34 and tank I1. The supply device constitutes a constant level maintaining feed ofthe bird fountain or Marriott bottle type. When the oil in the chamber 34 drops below the'end of the tube 33, gas flows upthrough the tube 33 permitting additional oilto ent/er thel chamber through the tube fromthe main bodyof oil 42. The mercury'seal .is gas tightand preventsl admission o'f air or gas which tends to enter through the pipe 40 as the top of the tank I8 is normally under suction. The level of oil ,in the chamber 34 and tank I1 is thuskept substantially even with the lower end of tube 33. The lowering of the oil in tank I3 allows `the pressure therein to rise and hence exert less pressure difference on the mercury seal, vone leg of which Vserves as an indicator inthe 'glass 38. y

'I'he two valves 35and A45 are connected for joint operation as by a bar or link 52' whichconnects the operating arms or cranks 53 and 54 of the valves 36 and 45, respectively. A common actuating member in the .shape of a bell crank lever 55 having an operating handle 5G is adapted to actuate both valves in unison. This handle 56 interlocks with the handle 51 of piston 44. Hence the valves 36 `and Y45 must be turned through such movement as will shift them to charging position--in this case -before the handle 51 of the pump plunger can be raised. Similarly the plunger handle 51 must be depressed before the lever 56 can be swung down to shift the valves to normal position.

To recharge the reservoir or tank I8 with oil,

the same time likewise .turned counterclockwiseV 90 from lthe position shown and thus establishes communication between an oil pressure supply line 41 and the pipe 46. The valve' 36 in the latter position cuts off communication with the tank I1. The piston 44 is then elevatedto draw the mercury of the seal into the cylinder or cup 43. Oil from the pressure line 41 is forced through pipe 46 into the chamber 34`and through tube 33 into they reservoir, compression of gas in the upper part ofthe tank I8 being relieved throughpipes 4D, 33, 38, 31 and 5I) and tank I1. The upper end or" the pipe 5I being closed by the valve'45, oil does not enter said pipe, and the portion of the chamber 34 above the level of the lower end ofthe tube 33 is likewise kept free of oil by the entrapped gas. The tank I 8 preferably has all its seams and joints welded and the various pipes entering the same may also be welded to the tank to prevent entrance of air into the tank I8 and thus avoid flooding the tank I1 with oil.

Bythe present improvements satisfactory fogging can be eifected with a pressure differential on the nozzles of only 3'to 5 pounds. With a greater differential the efficiency of the rapparatus is increased. It will be seen that no moving parts are employed in eiecting the atomization of the oil, no heat is used, and the power employed is obtained from the pressure of the gas conveyed to the nozzles.

The fog formed by the present improvements has been found to be very persistent, aording adequate oiling oi parts at a distance of ve thousand feet from the fogging station even when used in conjunction with a low pressure distribution system.

In Figures 7 and 8, we have shown a modification of the structure shown in Figure 3, said modication consisting essentially in the placing of the oil supply tank I8 around the atomizing tank I1 and causing the bottom of the atomizing tank I1 to act as a constant level chamber, thereby eliminating the special chamber 34 of Figure 3. Also, in Figures 7 and 8, the piping system has been appreciably simplified over the system as shown in Figure 3. The atomizing tank is indicated at 10, being essentially of the same construction as the tank l1. A bottom pan 1I is secured to the bottom of the tank 1li to enclose the various pipes and manifold connections for the nozzles within the tank, said pan being provided with a plurality of openings that are provided with closures 12. The tank 10, the nozzles therein, and the various connections to the nozzles may be of the type shown in Figure 3.

An oil feeding tank 15 surrounds the tank 10 and is provided with a bottom 16 comprising an annular ring that is welded to the outside of the tank 18 and to the outer Wall of the tank 15. Communication is provided between the bottom of the tank 15 and the bottom of the tank 10 by Way of a pipe connection 18, a three-way valve 19, and a connection 8D. An oil feed pipe 82 also extends to the three-way valve 19, the valve arrangement being such that the valve may establish communication between the connection 18 and the pipe 82, or between the connection 18 and the connection 80. During the normal operation of the system, the valve maintains the communication between the connection 18 and the connection 85 while closing the communication with the pipe 52. An equalizing pipe extends from the bottom of the tank 1B to adjacent the top of the tank 15, said equalizing pipe being, of course, open at both ends. It is to be noted that the lower end of the pipe 85 opens into the tank 1U at a point below the point where the pipe 8D opens into the tank 1Q.

An explanation will now be given of the mode of operation of the system for maintaining a constant oil level in the tank 10. Assume that the tank 15 is to be filled. The three-way valve 19 is turned to establish communication between the connection 18 and the oil feed pipe 32. Oil under pressure is forced into the tank 15 by way of the pipe 82. As the oil rises Within the tank 15 the gases therein are expelled by way of the equalizing pipe 85, said gases discharging into the atomizing tank 1l). Therefore the pressure upon the oil in the tank 15, when the tank is full, will be substantially the same as the gas pressure within the atomizing tank 1Q. The three-way valve 19 is now operated to close off communication with the pipe 82 and to establish communication between the connections 18 and 8D. Oil now flows from the tank 15 into the tank 1li until the level of the oil in the tank 19 is slightly above the pipe 80. During this time, gas from the tank 10 was able to bubble through the connection into the tank 15. The oil level in the tank 10 is above the level of the opening at the bottom of the equalizing pipe 35, and oil will rise in this pipe until it reaches the level of the oil in the tank 15. This level is below the top of the equalizing pipe 85, and therefore the equalizing pipe 85 does not play any part in the operation of the system after the tank 15 has been lled. i

It is only during the iilling of this tank that the equalizing pipe is necessary. After the oil in the bottom of the tank 10 has risen above the pipe 8B, no more oil can flow from the tank 15 into the tank 1G because of the vacuum that is created above the oil level in the tank 15. As the oil is atomized, due to the action of the nozzles, the oil level at the bottom of the tank 10 recedes slightly. When the oil level passes below the pipe 80, bubbles of gas from the tank 1D will pass through the pipe 80, then into the tank 15, and thus permit oil to flow from the tank 15 into the tank 1li. In this manner, the level of the oil in the tank 1U is maintained substantially constant.

It is apparent that the apparatus described is not limited to the use of oil only, as other liquids may be similarly atomized, if desired, either for treating gas or for analogous purposes. It will also be apparent that the reduction of the temperature of the fog may be eiected or ampliiied by methods or apparatus other than as described above, and also that the relative raising of the temperature of the gas, instead of a reduction in temperature of the fog, is within the scope and spirit of our invention. The invention is not limited to the precise arrangements herein shown, the same being merely illustrative. What we consider new, and desire to secure by Letters Patent 1s:

1. Means for fogging a stream of gas comprising a fogging tank, a plurality of atomizer nozzles in said tank, oil supply means therefor, means for passing said gas at high velocity past restrictions in said nozzles to pick up oil and atomize the same, the outlets of said nozzles providing substantially free expansion of said gas stream into the relatively unconned free space in said tank to prevent .impingement of oil particles on restricting surfaces, a distribution conduit, and means for passing the oil fogged gas stream from said tank to said conduit.

2. The combination of claim l further characterized by the provision of means for quantitatively varying one of said fogging constituents in accordance with the rate of ow of gas in said distribution conduit.

3. Fogging apparatus of the class described for fogging a stream of gas passing from a transmission conduit to a distribution conduit under a pressure differential of substantially less than ve pounds, comprising a fogging tank, an atomizing nozzle in said tank having an outwardly flaring outlet opening directly into a relatively free unconned space within said tank, means for supplying oil to said nozzle, means for increasing the velocity in said gas stream as it passes through said nozzle to produce atomization of said oil, said outlet providing for immediate substantially free expansion of said gas stream upon contact with said oil to prevent collision between oil particles in said stream and to provide for substantially free dispersal of said stream in all directions from said nozzle within said tank, and means for introducing the fogged gas stream from said tank into said distribution conduit.

MATHEW G. MARKLE. LOREN W. TUTTLE. 

